Serializer/Deserializers (Ser/Des) are devices that can take wide bit-width, single-ended signal buses and compress them to a few, and often times one, differential signal that switches at a much higher frequency rate than the wide single-ended data bus. A SerDes is often used in high-speed communication networks and is typically an Integrated Circuit (IC) transceiver. In other words, the SerDes provides the interface between a core of an IC or similar processor core and the communication channel used to carry information to/from the core of the IC or processor.
SerDes applications with higher data rates are trying to strive for better power efficiency (mW/Gbps). Meanwhile, some applications and standards require the transmitter output to be as high as 1.2V (differential peak-to-peak). There are some problems with using a conventional voltage mode driver for providing as high as 1.2V differential swings at the output, including: (1) reliability concerns (oxide breakdown in case of thin oxide devices); (2) higher power consumption due to the transmission circuits using a 1.2V supply when not needing it; and (3) level shifters are needed to raise the signal domain from a lower supply that the Serializers and other preceding circuits use.